The present invention relates to a semiconductor module and a power converting apparatus using the semiconductor module.
In recent years, for power semiconductor modules, a current capacity has been wide-ranged from several amperes to several thousands of amperes, a size has been reduced, and a cost has been lowered. In order to achieve the miniaturization, cost reduction and reliability enhancement, in these power semiconductor modules, a case and an electrode in which a part of the electrode is integrally formed with the resin portion in a module case (hereinafter referred to as the lead insert case) are used. As one example, a technique is described in Japanese Patent Unexamined Publication No. 07-263621. However, in the class of several amperes to several tens of amperes, since the miniaturization and special configuration of an application itself have been advanced, and the customizing of the module has been requested. Examples of requirements from the application include a module outer shape, height, electrode position, and the like, particularly the requirements for the electrode position differ with the respective applications and the insert case integrally provided with the electrode in which a peculiar layout is possible is required. For this purpose, dies for integrally forming the case and electrode and extracting the electrode have to be manufactured for each requirement, and enormous initial investment and development period have been necessary.
Moreover, in recent years, a module has also been proposed in which a general-purpose connector formed by outserting the electrode to resins such as polybutylene terephthalate (PBT) prepared separately from a module outer case resin is directly fixed, by using a solder, to a copper foil pattern disposed beforehand on an insulating layer in the module. In this case, the electrode can be disposed without being influenced by a module shape. Additionally, since the general-purpose connector is utilized, the cost can be reduced, the development period can be shortened, and custom requirements can be handled. However, since the electrode is fixed by the solder, the soldered part, the insulating layer right under the copper foil pattern and the like are destroyed by stresses applied to the solder between the electrode and the copper foil pattern, the copper foil pattern, and the insulating layer right under the copper foil pattern from the inside or outside of the module, thereby causing reliability deterioration such as insulation defect and wire breaking.
According to the above-described conventional art, the lead insert case is used to advance the miniaturization and reliability enhancement, while the general-purpose connector is used to lower the cost and shorten the development period.
However, in order to customize the power semiconductor module, when the lead, insert case is used, the scope of the free design is lowered, and the enormous initial investment and long development period are necessary. Moreover, when the general-purpose connector is used, there arises a problem that the reliability is deteriorated.
An object of the present invention is to provide a semiconductor module which avoids the deterioration of the scope of the free design of a custom module for various applications, reduces a size, lowers a cost, enhances a reliability and shortens a development period.
To solve the above-described problem, according to the present invention, there is provided a semiconductor module in which a lead electrode is covered with a resin member separated from a case, and a connector securing a space for bonding a metal wire to the electrode part is bonded to a substrate with a emiconductor element mounted thereon.
With such a connector, the electrode can be disposed in an appropriate position in the power semiconductor module without being largely influenced by a module case shape and the scope of free layout is improved, while the custom module can be provided without developing a lead insert case for each requirement from each application, which enables the cost reduction, reliability enhancement, initial investment reduction, and shortened development period.
Moreover, since the electric connection between the connector and a wiring pattern to connect the semiconductor element mounted on the semiconductor module to other circuit components is performed not by soldering, but by the bonding of the metal wire, the reliability against the wire breaking, insulation, and the like can be improved.
When the semiconductor module according to the present invention is applied to power converting apparatuses such as an inverter, the scope of the free arrangement of the semiconductor module and the substrate with other electric circuit components is increased. Therefore, the power converting apparatus can be miniaturized.
According to the present invention, there is provided another semiconductor module comprising: a resin case; a semiconductor element disposed in the resin case; a lead electrode electrically connected to the semiconductor element and extracted to the outside of the resin case; and a substrate with electric circuit components mounted thereon. Further, the substrate is positioned over the semiconductor element, and removably connected to the lead electrode. As a concrete constitution of the above semiconductor module, there is a structure that the substrate with the electric circuit components mounted thereon is removably connected to the lead electrode in the above described semiconductor module according to the present invention.
According to the present invention, there is provided another power converting apparatus comprising: a resin case, a semiconductor module provided with the resin case, a semiconductor element disposed in the resin case, and a lead electrode electrically connected to the semiconductor element and drawn to the outside of the resin case; and a substrate with electric circuit components mounted thereon. Further, the substrate is positioned above the semiconductor module, and removably connected to the lead electrode. As a concrete constitution of another power converting apparatus according to the present invention, the above-described concrete constitution of another semiconductor module of the present invention is applied.
With another semiconductor module and power converting apparatus according to the present invention, various types and series of the semiconductor modules and the power converting apparatuses can easily be obtained. Therefore, the costs of the semiconductor module and the power converting apparatus can be lowered.